Gear Ratio Calculator – Driven Teeth ÷ Driver Teeth
Calculate a simple driven-to-driver gear ratio from the two gear tooth counts.
For a simple pair of meshing gears, this calculator reports the tooth-count ratio of the driven gear to the driver gear.
How it works
Gear ratio = driven gear teeth / driver gear teeth.
Example
A 40-tooth driven gear and 20-tooth driver gear give a ratio of 40/20 = 2.
How to use
- Enter the driver gear tooth count.
- Enter the driven gear tooth count.
- Calculate the ratio.
- Interpret values above or below 1 according to the direction of the gear pair.
Key features
- Tooth-count based ratio
- Positive-value validation
- Simple two-gear model
- Browser calculation
Common uses
- Robotics gear-train examples
- Mechanical ratio checks
- Comparing different tooth-count combinations
Frequently asked questions
Does this calculator include multiple gear stages?
No. It calculates the simple ratio of one driven gear to one driver gear.
Why use tooth counts?
For meshing gears, tooth counts provide the same simple ratio relationship as pitch diameters.
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